This competing continuation proposal for a Data Management Center (DMC) is submitted in conjunction with a parallel proposal entitled "Randomized Trial of ORG 10172 in Acute or Progressing Ischemic Stroke" submitted simultaneously by Harold P. Adams, Jr., M.D. The clinical aspects of this research are documented in Dr. Adams' proposal. Briefly, a promising class of drugs called low molecular weight heparins, or heparinoids, which have selective antithrombotic effects without the anticoagulant or platelet-aggregating properties of heparin, may be effective in treating patients with acute ischemic stroke. One such heparinoid, ORG 10172, is being tested in this multi-center, randomized, double-blind, placebo- controlled trial. The primary hypothesis is that, in a population of patients with acute ischemic stroke, ORG 10172 is more efficacious than placebo in improving the likelihood of a favorable outcome (Glasgow Outcome Scale of I or II and Barthel Index of 12 or more) at three months after stroke. A total of 1300 patients will be randomly assigned to a seven-day intravenous infusion of either ORG 10172 or placebo within 24 hours of stroke onset. Patients are followed for three months post randomization, or until death. The primary reasons for extending funding are to continue patient enrollment to the target sample size, and to conduct additional statistical analyses. The Data Management Center (DMC) works closely with the Clinical Coordinating Center (CCC - Dr. Adams' group) in managing the trial, coordinating the biostatistical and data management aspects of the trial, and monitoring patient safety. The DMC is responsible for providing a variety of data management services, including receiving, tracking, editing, and correcting data collected at the 26 Participating Clinical Centers (PCCs). The DMC uses a secure, personal computer based Novell local area network for data base and file storage, printing, and remote communications services. The DMC developed a distributed data entry system for this trial, whereby data are double-key entered at the PCC and electronically transmitted to the DMC. The DMC provides the PCCs with personal computers, and trains study coordinators in using the system. The DMC provides regular reports to the PCCs regarding overdue data and data requiring correction, to the CCC regarding recruitment and payment processing, and to NIH regarding progress and safety in the trial. A group of physicians within the DMC, the In-House Safety Committee, reviews data monthly in an unblinded fashion, monitoring adverse experience trends. If the In-House Safety Committee has concerns about safety, the chair of the NIH Safety and Monitoring Committee is notified. The DMC performs all statistical analyses associated with this trial, including safety analyses and formal interim and final analyses. Investigator-initiated requests from the PCCs for analyses of baseline TOAST data are forwarded to the DMC, where analyses are performed and statistical guidance and interpretation are offered to the local investigator.